Method, alert control device, street light, computer program and computer program product for alerting traffic

ABSTRACT

It is provided a method for alerting traffic. The method is performed in an alert control device connected to a street light and comprises the steps of: detecting the presence of a radio frequency identification device using a radio frequency identification reader; and controlling the street light to go from a normal state to an alert state, wherein the lighting of the street light in the alert state differs from the lighting of the street light in the normal state. Alert control devices, a street light, a computer program and a computer program are also presented.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application is a 35 U.S.C. § 371 National Phase Entry Applicationfrom PCT/SE2013/050931, filed Jul. 26, 2013, designating the UnitedStates, the disclosure of which is incorporated by reference.

TECHNICAL FIELD

The invention relates to alerting traffic by altering the state of astreet light.

BACKGROUND

Road accidents are a serious problem affecting people worldwide. InMarch 2013, the World Health Organisation published a report (availableat http://www.who.int/mediacentre/factsheets/fs358/en/ at the time offiling this application) on road accidents, concluding several alarmingfacts:

-   -   About 1.24 million people die each year as a result of road        traffic crashes.    -   Road traffic injuries are the leading cause of death among young        people, aged 15-29 years.    -   91% of the world's fatalities on the roads occur in low-income        and middle-income countries, even though these countries have        approximately half of the world's vehicles.    -   Half of those dying on the world's roads are “vulnerable road        users”: pedestrians, cyclists and motorcyclists.    -   Without action, road traffic crashes are predicted to result in        the deaths of around 1.9 million people annually by 2020.    -   Only 28 countries, representing 416 million people (7% of the        world's population), have adequate laws that address all five        risk factors (speed, drink-driving, helmets, seat-belts and        child restraints).

Main causes of road accidents have been concluded to relate to speed,drink-driving, lack of helmet use, lack of use of seat belts and childrestraints and distracted driving. Focusing on speed and distracteddriving, the WHO have published their findings as follows.

Regarding speed, it has been found that an increase in average speed isdirectly related both to the likelihood of a crash occurring and to theseverity of the consequences of the crash.

Regarding distracted driving, there are many types of distractions thatcan lead to impaired driving, but recently there has been a markedincrease around the world in the use of mobile phones by drivers that isbecoming a growing concern for road safety. The distraction caused bymobile phones can impair driving performance in a number of ways, e.g.longer reaction times, impaired ability to keep in the correct lane, andshorter following distances. Text messaging also results in considerablyreduced driving performance, with young drivers at particular risk ofthe effects of distraction resulting from this use. A driver using amobile phone is approximately four times more likely to be involved in acrash than when a driver does not use a mobile phone. Hands-free phonesare not much safer than hand-held phone sets. While there is littleconcrete evidence yet on how to reduce mobile phone use while driving,governments need to be proactive. Actions that can be taken includeadopting legislative measures, launching public awareness campaigns, andregularly collecting data on distracted driving to better understand thenature of this problem.

Drivers can also be distracted by other devices, such as GPS (GlobalPositioning System) receivers, video players and other infotainmentdevices.

In light of latest facts on road safety, a key problem is thevulnerability of unprotected road users such as pedestrians andcyclists. It would be greatly beneficial if there was an efficient wayto alert traffic of unprotected road users to reduce the risk ofaccidents.

The use of street lights helps drivers to see unprotected road users butdistracted drivers may still not be alert enough to notice theunprotected road users.

Traffic lights can be used to stop traffic e.g. when unprotected roadusers need to cross the road. However, traffic lights are expensive andcan not be installed everywhere there are pedestrians and cyclists,particularly in low and middle income countries.

SUMMARY

It is an object to provide a way to alert traffic of an unprotected roaduser.

According to a first aspect, it is provided a method for alertingtraffic. The method is performed in an alert control device connected toa street light and comprises the steps of: detecting the presence of aradio frequency identification (RFID) device using a radio frequencyidentification reader; and controlling the street light to go from anormal state to an alert state, wherein the lighting of the street lightin the alert state differs from the lighting of the street light in thenormal state. In this way, when a user carrying an RFID deviceapproaches alert control device connected to a street light, anyvehicles in the road are clearly alerted of the presence of the user,reducing the risk of a vehicle hitting the user, e.g. when the userneeds to cross the road. Significantly, there can be many street lightswith associated alert control devices, whereby each street light/alertcontrol device combination can be atomic and does not need to beconnected to any other controller for operation, even if this is alsopossible. This greatly simplifies deployment and cost, e.g. compared todeploying traffic lights which are typically also only provided atintersections; alerting street lights can be deployed at arbitrarylocations along a road where unprotected road users are frequent.Moreover, compared to traffic lights, this solution does not commandtraffic to stop, which is less obtrusive to traffic and can thusincrease acceptance of this solution.

The step of detecting may comprise detecting a radio frequencyidentification device with an identifier being within a predefinedrange. This allows the definition of a specific set of RFID deviceswhich are to trigger the alert state of the street light.

In the step of controlling, the alert state may involve an alteredcolour compared to the normal state.

In the step of controlling, the alert state may involve an altered lightintensity compared to the normal state. This is another way of alertingdrivers without the need of having a street light with alterable colour.

The method may further comprise the steps of: detecting an absence ofany radio frequency identification devices using the radio frequencyidentification reader; and controlling the street light to go from thealert state to the normal state. In other words, the street light thenreturns to the normal state when the RFID device is not in rangeanymore.

The step of detecting an absence of any radio frequency identificationdevices may comprise detecting an absence of any radio frequencyidentification devices during a configurable time period. This canprevent the street light from returning to normal state when the usercarrying the RFID device is still on the road but outside a detectionrange of the alert control device.

The alert control device may be connected to two street lights on eitherside of a road in which case the step of controlling the street lightcontrols both street lights the same way. This makes crossing a roadsafer, since the alert to traffic is even more noticeable.

The step of detecting the presence of a radio frequency identificationdevice may comprise detecting, using a near field communication (NFC)reader, the presence of a radio frequency identification devicecomprised in a near field communication compliant wireless communicationdevice. NFC communication typically requires a distance of 10 cm or lessand works at 13.56 MHz frequency. This short distance can be used todetect intent, distinguishing between users which are present by astreet light and users intending to enter the road, e.g. to cross theroad.

The step of detecting the presence of a radio frequency identificationdevice may comprise detecting the presence of a battery powered radiofrequency identification device which is activated by a user. This isanother way of a user being able to indicate an intent to enter theroad.

The method may further comprise the step of: storing log data regardingwhen the step of controlling the street light to go from a normal stateto an alert state has occurred. The log data can be used to analysepatterns of usage, which then serves as an indicator of unprotected roaduser presence.

According to a second aspect, it is provided an alert control device foralerting traffic. The alert control device is arranged to be connectedto a street light, and the alert control device comprises: a processor;and a memory storing instructions that, when executed by the processor,causes the alert control device to: detect a presence of a radiofrequency identification device using a radio frequency identificationreader; and control the street light to go from a normal state to analert state, wherein the lighting of the street light in the alert statediffers from the lighting of the street light in the normal state.

The instructions to detect may comprise instructions that, when executedby the processor, causes the alert control device to detect a radiofrequency identification device with an identifier being within apredefined range.

The alert state may involve an altered colour compared to the normalstate.

The alert state may involve an altered light intensity compared to thenormal state.

The alert control device may further comprise instructions that, whenexecuted by the processor, causes the alert control device to: detect anabsence of any radio frequency identification devices using the radiofrequency identification reader; and control the street light to go fromthe alert state to the normal state.

The instructions to detect an absence of any radio frequencyidentification devices may comprise instructions that, when executed bythe processor, causes the alert control device to detect an absence ofany radio frequency identification devices during a configurable timeperiod.

The alert control device may be connected to two street lights on eitherside of a road in which case the alert control device is arranged tocontrol both street lights the same way.

The instructions to of detect the presence of a radio frequencyidentification device may comprise instructions that, when executed bythe processor, causes the alert control device to detect, using a nearfield communication reader, the presence of a radio frequencyidentification device comprised in a near field communication compliantwireless communication device.

The instructions to detect the presence of a radio frequencyidentification device may comprise instructions that, when executed bythe processor, causes the alert control device to detect the presence ofa battery powered radio frequency identification device which isactivated by a user.

The alert control device may further comprise instructions that, whenexecuted by the processor, causes the alert control device to: store logdata regarding when the street light is controlled to go from a normalstate to an alert state has occurred.

According to a third aspect, it is provided an alert control devicecomprising means for detecting the presence of a radio frequencyidentification device using a radio frequency identification reader; andcontrolling a street light, connected to the alert control device, to gofrom a normal state to an alert state, wherein the lighting of thestreet light in the alert state differs from the lighting of the streetlight in the normal state.

The means for detecting may comprise means for detecting a radiofrequency identification device with an identifier being within apredefined range.

The alert state may involve an altered colour compared to the normalstate.

The alert state may involve an altered light intensity compared to thenormal state.

The alert control device may further comprise means for detecting anabsence of any radio frequency identification devices using the radiofrequency identification reader; and means for controlling the streetlight to go from the alert state to the normal state.

The means for detecting an absence of any radio frequency identificationdevices may means for detecting an absence of any radio frequencyidentification devices during a configurable time period.

The alert control device may be connected to two street lights on eitherside of a road in which case the means for of controlling the streetlight comprises means for controlling both street lights the same way.

The means for detecting the presence of a radio frequency identificationdevice may comprise means for detecting, using a near fieldcommunication reader, the presence of a radio frequency identificationdevice comprised in a near field communication compliant wirelesscommunication device.

The means for detecting the presence of a radio frequency identificationdevice may comprise means for detecting the presence of a batterypowered radio frequency identification device which is activated by auser.

The alert control device may further comprise means for storing log dataregarding when controlling the street light to go from a normal state toan alert state has occurred.

According to a fourth aspect, it is provided a street light comprisingthe alert control device according to the second aspect or the thirdaspect.

According to a fifth aspect, it is provided a computer programcomprising computer program code. The computer program code, when run ona alert control device connected to a street light, causes the alertcontrol device to: detect a presence of a radio frequency identificationdevice using a radio frequency identification reader; and control thestreet light to go from a normal state to an alert state, wherein thelighting of the street light in the alert state differs from thelighting of the street light in the normal state.

According to a sixth aspect, it is provided a computer program productcomprising a computer program according to the fifth aspect and acomputer readable means on which the computer program is stored.

Generally, all terms used in the claims are to be interpreted accordingto their ordinary meaning in the technical field, unless explicitlydefined otherwise herein. All references to “a/an/the element,apparatus, component, means, step, etc.” are to be interpreted openly asreferring to at least one instance of the element, apparatus, component,means, step, etc., unless explicitly stated otherwise. The steps of anymethod disclosed herein do not have to be performed in the exact orderdisclosed, unless explicitly stated.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is now described, by way of example, with reference to theaccompanying drawings, in which:

FIG. 1 is a schematic diagram illustrating alerting traffic according toone embodiment;

FIG. 2 is a schematic diagram illustrating alerting traffic according toone embodiment when an unprotected road user crosses the road;

FIG. 3 is a schematic diagram illustrating alerting traffic according toone embodiment where street lights opposite each other are connected;

FIG. 4 is a schematic diagram illustrating alerting traffic according toone embodiment where near field communication (NFC) is used;

FIGS. 5A-B are state diagrams illustrating the operation of the streetlight of FIGS. 1-4;

FIGS. 6A-B are flow charts illustrating methods for alerting traffic,performed in the alert control device of FIGS. 1-4;

FIG. 7 is a schematic diagram showing some components of the alertcontrol device of FIGS. 1-4;

FIG. 8 is a schematic diagram showing functional modules of the alertcontrol device of FIGS. 1-4; and

FIG. 9 shows one example of a computer program product comprisingcomputer readable means.

DETAILED DESCRIPTION

The invention will now be described more fully hereinafter withreference to the accompanying drawings, in which certain embodiments ofthe invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein; rather, these embodiments are provided byway of example so that this disclosure will be thorough and complete,and will fully convey the scope of the invention to those skilled in theart. Like numbers refer to like elements throughout the description.

FIG. 1 is a schematic diagram illustrating alerting traffic according toone embodiment. There is a road 8 where vehicles 6 can drive. On one orboth sides of the road 8, there are street lights 3. Each street light 3has an associated (internal or external) alert control device 1. A user7 carries a radio frequency identification (RFID) device 4. The user 7is an unprotected road user, such as a pedestrian or cyclist.

The RFID device can e.g. be an RFID tag embodied in daily usage items.RFID tags can be produced at very low unit cost. For example, the user 7can carry an RFID tag being part, or attached to a wirelesscommunication device (such as a mobile communication terminal,smartphone, tablet computer or similar), a case or cover of a wirelesscommunication device, belt, walking stick, laptop bag, ladies purse,belt or chain of pet dog, pram, portable audio media player, bicycleseat, bicycle light, watch, clothing, shoes, etc.

When the alert control device 1 of a street light 3 detects the presenceof the RFID device 4, the alert control device controls the street light3 to go from a normal state to an alert state, e.g. by changing colourand/or intensity, as indicated by the dashed lines by the street light 3in the middle on the lower side of the road 8 in FIG. 1.

In this way, when the user 7 carrying the RFID device 4 approaches astreet light 3, the vehicles 6 are clearly alerted of the presence ofthe user, reducing the risk of a vehicle 6 hitting the user 7, e.g. whenthe user needs to cross the road. Significantly, each street light3/alert control device 1 combination can be atomic and does not need tobe connected to any other controller for operation, even if this is alsopossible. This greatly simplifies deployment and cost, e.g. compared todeploying traffic lights which are typically also only provided atintersections; alerting street lights can be deployed at arbitrarylocations along a road where unprotected road users are frequent.Moreover, compared to traffic lights, this solution does not commandtraffic to stop, which is less obtrusive to traffic and can thusincrease acceptance of this solution. Also, the use of street lights isgreatly effective in alerting traffic, since the driver is clearly madeaware of the user 7.

If a cyclist rides a bike along the road 8 carrying an RFID device 4,alert control devices 1 by street lights will detect the RFID device asit moves along, alerting traffic of the presence of the cyclist.

FIG. 2 is a schematic diagram illustrating alerting traffic according toone embodiment when an unprotected road user crosses the road. Here,compared to the situation shown in FIG. 1, the user 7 is in the processof crossing the road 8 and is approaching the top middle street light 3and its alert control device 1, whereby the top middle street light 3 iscontrolled to go into the alert state, further indicating to trafficthat there is an unprotected road user.

When the RFID device 4 is out of range of the alert control device 1,the street light 3 is controlled by the alert control device 1 to returnto the normal state. Optionally, the return to normal state only occursafter a configurable time period after the RFID device 4 is out of rangeto prevent the street light 3 from returning to normal state when theuser 7 is still on the road but outside a detection range of the alertcontrol device 1.

FIG. 3 is a schematic diagram illustrating alerting traffic according toone embodiment where street lights opposite each other are connected tothe same alert control device(s) 1. In this way, street lights 3 acrossfrom each other are controlled synchronously to better alert traffic ofthe presence of an unprotected road user.

FIG. 4 is a schematic diagram illustrating alerting traffic according toone embodiment where NFC is used. The alert control device 1 herecomprises an NFC reader. NFC is commonly used for contactlessshort-range communications based on radio frequency identification(RFID) standards, using magnetic field induction to enable communicationbetween electronic devices, including wireless communication devices.This short-range high frequency wireless communications technologyexchanges data between devices over a short distance, such as only a fewcentimeters. NFC communication typically requires a distance of 10 cm orless and works at 13.56 MHz frequency. This short distance can be usedto detect intent, distinguishing between users which are present by astreet light and users intending to enter the road, e.g. to cross theroad.

For example, a first user 7 a and a second user 7 b each carries awireless communication device 2 (such as a mobile communicationterminal, smartphone, tablet computer or similar) which comprises an NFCdevice 4′ which thus is an RFID device. In other words, the wirelesscommunication device 2 is NFC compliant. Here the presence of a user 7a-b is only detected by detecting the presence of the NFC device 2 dueto a user action, e.g. by tapping the NFC device on the alert controldevice 1. Hence, the first user 7 a, tapping the NFC device 2 on thealert control device 1 causes the connected street light 3 to go intothe alert state. However, the second user 7 b, while being in theproximity of another alert control device 1, does not cause the streetlight 3 connected to the other alert control device 1 to go into analert state.

The user action of the NFC device differentiates users actuallyintending to cross the road from users which are only by the side of theroad but have no intent of crossing the road. This reduces the number ofunnecessary alerts due to users being close to the alert control device1, whereby the alerts only relate to users with the intent to alerttraffic, e.g. for crossing the road or having to go into the road forother reasons.

Optionally, the wireless device 2 is an NFC device and also comprises aseparate RFID tag 4, being part of or attached to the wireless device 2.In that way, the alert control device 1 can distinguish between userpresence and user intent. In one embodiment, the alert control device 1is arranged to alert, using the connected street light in different wayswhen there is only user presence and no user intent, compared to whenthere is user intent (and optionally also user presence). For example,looking to FIG. 4, the middle lower traffic light 3, where the connectedalert control device 1 detects intent to enter the road 8 by the firstuser, can be controlled to have a more intense light or different colourcompared to the lower right traffic light 3, where only a presence ofthe second user 7 b is detected.

The alert control devices 1 are able to distinguish between an NFCdevice 4′ and an RFID tag 4. In one embodiment, this can be achieved bythe alert control device comprising an RFID reader and an NFC reader,which work on different frequencies. For example, at the time of filingthis patent application, NFC only works over 13.56 MHz, while RFID havemultiple frequencies on which it can operate. Alternatively oradditionally, the identifiers for the NFC devices and RFID tags arewithin different predefined ranges allow distinction between NFC devicesand RFID tags.

FIGS. 5A-B are state diagrams illustrating the operation of any one ofthe street lights 3 of FIGS. 1-4. First, the state diagram shown in FIG.5A will be described.

In the normal state 10, the traffic light operates as normal, lightingthe road and optionally roadside by the street light. When in the normalstate 10, the street light transitions to the alert state 11 when anRFID device is detected 15 by a connected alert control device.

In the alert state 11, the lighting of the street light differs from thelighting of the street light in the normal state 10. In one embodiment,in the alert state 11, the street light shines with a different colourthan when in the normal state 10. Alternatively or additionally, thealert state 11 involves an altered light intensity compared to thenormal state 10. The altered light intensity can e.g. be that the streetlight shines brighter or that the light intensity varies over time, e.g.by blinking. Alternatively or additionally, the altered light intensitycan comprise that the street light is on at daytime, compared to beingoff in the normal state 10.

When in the alert state 11, the street light transitions to the normalstate 10 when the absence of an RFID device is detected 16 by theconnected alert control device. If a new RFID device is detected 15 bythe connected alert control device, the street light is controlled tostay in the alert state 11.

Looking now to the state diagram of FIG. 5B, there is here also a waitstate 12. When in the alert state 11, the street light transitions tothe wait state 12 when the absence of an RFID device is detected 16 bythe connected alert control device. In the wait state 12, when a timerexpires 17, the street light transitions to the normal state 10. On theother hand, when in the wait state 12, if an RFID device is detected 15by the connected alert control device, the street light is controlled toreturn to the alert state 11.

Using the wait state 12, the risk of prematurely returning to the normalstate 10 from the alert state 11 is reduced, e.g. if the user is stillin the road but outside the detection range of any alert control devices1.

FIGS. 6A-B are flow charts illustrating methods for alerting traffic,performed in the alert control device of FIGS. 1-4. First, theembodiment of FIG. 6A will be described.

In a conditional detect presence step 30, it is checked whether thepresence of an RFID device can be detected using an RFID reader. TheRFID reader can be part of the alert control device or external to thealert control device but connected to it. If the presence of the RFIDdevice is detected, the method proceeds to a control to alert step 32.Otherwise, the method re-executes the conditional detect presence step30, optionally after an idle period.

Optionally, only RFID devices having identifiers within a predefinedrange are considered in the detection. In this way, the detecting can belimited to predefined RFID tags/NFC devices which are associated withalerting traffic by changing the alert state of the street light.

The detecting can e.g. involve detecting, using an NFC reader, thepresence of an NFC device comprised in an NFC compliant wirelesscommunication device (2 of FIG. 4). The NFC compliant wirelesscommunication device may then need to be tapped on the NFC reader of thealert control device, which necessitates an action by the user. The useraction differentiates users actually intending to cross the road fromusers which are only by the side of the road but have no intent ofcrossing the road. This reduces the number of unnecessary alerts due tousers being close to the alert control device, whereby the alerts onlyrelate to users with the intent to alert traffic, e.g. for crossing theroad or having to go into the road for other reasons.

Alternatively or additionally, the detecting comprises detecting thepresence of a battery powered RFID device which is explicitly activatedby a user. E.g. using a button on the RFID device. Such activation ofthe RFID device is another way of a user showing intent to alerttraffic.

In the control to alert step 32, the street light connected to the alertcontrol device 1 is controlled to go from the normal state to the alertstate as described above with reference to FIGS. 5A-B. As describedabove, the alert state can involve an altered colour and/or alteredlight intensity compared to the normal state. The altered lightintensity can e.g. be that it is brighter or that the light intensityvaries over time, e.g. by blinking.

As explained with reference to FIG. 3 above, the alert control devicemay optionally be connected to two street lights on either side of theroad. The control to alert step 32 of then controls both street lightsthe same way. This also makes crossing a road safer, since the alert totraffic is even more noticeable.

FIG. 6B is a flow chart illustrating one embodiment of a method fordownloading an electronically transferable subscriber identity module.The method of FIG. 6B is similar to the method of FIG. 6A and only stepswhich are new or modified compared to the method of FIG. 6A aredescribed here. In this embodiment, the absence of an RFID device ishandled and also logging is performed.

After the control to alert step 32, there is here a conditional detectabsence step 34. In the conditional detect absence step 34, it ischecked whether the absence of an RFID device can be detected using theRFID reader. If the absence of the RFID device is detected, the methodproceeds to a control to normal step 36. Otherwise, the methodre-executes the conditional detect absence step 34, optionally after anidle period.

Optionally, the alert control device only considers the absence of anyRFID device to be detected when an absence of any RFID devices ismaintained during a configurable time period. In this way, the streetlight stays in alert mode longer than only when the RFID tag/NFC deviceis out of range, which can e.g. make it safer for a pedestrian to crossa road as the range of the detecting range of the alert control devicemay only cover part of the road crossing.

In the control to normal step 36, the street light connected to thealert control device 1 is controlled to go from the alert state to thenormal state as described above with reference to FIGS. 5A-B.

In an optional store log data step 38, log data is stored regarding whenthe street light is controlled to go from the normal state to the alertstate, and/or vice versa has occurred. The log data can be storedlocally and collected by operators or the alert control device isoptionally provided with a wireless communication module, providing thelog data to a central server. The log data can be used to analysepatterns of usage, being an indicator of unprotected road user presence.

FIG. 7 is a schematic diagram showing some components of the alertcontrol device of FIGS. 1-4. A processor 50 is provided using anycombination of one or more of a suitable central processing unit (CPU),multiprocessor, microcontroller, digital signal processor (DSP),application specific integrated circuit etc., capable of executingsoftware instructions 56 stored in a memory 54, which can thus be acomputer program product. The processor 50 can be configured to executethe method described with reference to FIGS. 6A-B above.

The memory 54 can be any combination of read and write memory (RAM) andread only memory (ROM). The memory 54 also comprises persistent storage,which, for example, can be any single one or combination of magneticmemory, optical memory, solid state memory or even remotely mountedmemory.

Optionally, the alert control device 1 further comprises an I/Ointerface 52 for communicating with other entities, such as to controlthe state of a street light. The I/O interface 52 may also comprise auser interface to allow an operator to control the operation of thealert control device 1.

The alert control device 1 also comprises an RFID reader 51 fordetecting the presence of an RFID device, e.g. an RFID tag. Optionally,the RFID reader 51 uses NFC, e.g. complying with ISO/IEC 18092:2013.Optionally, the RFID reader 51 comprises modules for reading both RFIDtags and NFC devices, optionally on different frequencies.

A data memory 53 is also provided for reading and/or storing data duringexecution of software instructions in the processor 50. The data memory53 can be any combination of read and write memory (RAM) and read onlymemory (ROM). The data memory 53 here also comprises log data ≡regardingwhen the street light is controlled to go from the normal state to thealert state, and/or vice versa has occurred.

The alert control device 1 is in contact with at least one street light,where the alert control device 1 can be part of the street light orexternal to, but connected to the street light.

Other components of the alert control device 1 are omitted in order notto obscure the concepts presented herein.

FIG. 8 is a schematic diagram showing functional modules of the alertcontrol device 1 of FIGS. 1-4. The modules can be implemented usingsoftware instructions such as a computer program executing in the alertcontrol device 1 and/or using hardware, such as application specificintegrated circuits, field programmable gate arrays, discrete logicalcomponents, etc. The modules correspond to the steps in the methodsillustrated in FIGS. 6A-B.

A detector 60 is arranged to detect a presence of a radio frequencyidentification device using a radio frequency identification reader.This module corresponds to the detect presence step 30 of FIGS. 6A-B andthe detect absence step 34 of FIG. 6B.

A state controller 62 is arranged to control the street light to go froma normal state to an alert state or vice versa. This module correspondsto the control to alert step 32 of FIGS. 6A-B and the control to normalstep 36 of FIG. 6B.

A logger 64 is arranged to store log data regarding when the streetlight is controlled to go from a normal state to an alert state hasoccurred. This module corresponds to the store log data step 38 of FIG.6B.

FIG. 9 shows one example of a computer program product 90 comprisingcomputer readable means. On this computer readable means a computerprogram 91 can be stored, which computer program can cause a processorto execute a method according to embodiments described herein. In thisexample, the computer program product is an optical disc, such as a CD(compact disc) or a DVD (digital versatile disc) or a Blu-Ray disc. Asexplained above, the computer program product could also be embodied ina memory of a device, such as the computer program product 56 of FIG. 7or e.g. on a USB (Universal Serial Bus) drive (not shown). While thecomputer program 91 is here schematically shown as a track on thedepicted optical disk, the computer program can be stored in any waywhich is suitable for the computer program product.

The invention has mainly been described above with reference to a fewembodiments. However, as is readily appreciated by a person skilled inthe art, other embodiments than the ones disclosed above are equallypossible within the scope of the invention, as defined by the appendedpatent claims.

The invention claimed is:
 1. A method for alerting traffic, the methodbeing performed in an alert control device connected to a street light,the method comprising: receiving a first signal transmitted by a firstdevice within the possession of a first individual within a proximity ofthe street light, wherein the first individual is one of a pedestrianand a cyclist, the first signal being received via a near fieldcommunication (NFC) technology; after receiving the first signal,determining that the first individual intends to cross a street withinthe proximity of the street light; and as a result of determining thatthe first individual intends to cross the street, controlling the streetlight to go from a normal state to a first alert state, wherein thelighting of the street light in the first alert state differs from thelighting of the street light in the normal state in order to alertpassing vehicles that the first individual may be crossing the streetwithin the proximity of the street light; receiving a second signaltransmitted by a second device within the possession of a secondindividual; determining that a NFC signal from the second device has notbeen received; and based on the receipt of the second signal and thedetermination that the NFC signal from the second device has not beenreceived, determining that the second individual is within the proximityof the street light but does not intend to cross the street.
 2. Themethod of claim 1, wherein the first alert state involves an alteredcolor compared to the normal state.
 3. The method of claim 1, whereinthe first alert state involves an altered light intensity compared tothe normal state.
 4. The method of claim 1, further comprising the stepsof: detecting an absence of any radio frequency identification devicesusing the alert control device; and controlling the street light to gofrom the first alert state to the normal state.
 5. The method of claim4, wherein the step of detecting an absence of any radio frequencyidentification devices comprises detecting an absence of any radiofrequency identification devices during a configurable time period. 6.The method of claim 1, wherein the alert control device is connected totwo street lights on either side of a road and wherein the step ofcontrolling the street light controls both street lights the same way.7. The method of claim 1, wherein at least one of the first signal andthe second signal is received via a battery powered radio frequencyidentification device which is activated by a user.
 8. The method ofclaim 1, further comprising the step of: storing log data regarding whenthe step of controlling the street light to go from a normal state tothe first alert state has occurred.
 9. The method of claim 1, whereinthe first signal is detectable over a maximum range of approximately 10centimeters.
 10. The method of claim 1, wherein the method furthercomprises: as a result of determining that the second individual iswithin the proximity of the street light but does not intend to crossthe street, controlling the street light to enter a second alert state,wherein the lighting of the street light in the second alert statediffers from the lighting of the street light in the first alert state.11. An alert control device for alerting traffic, the alert controldevice being arranged to be connected to a street light, the alertcontrol device comprising: a receiver configured to receive a firstsignal transmitted by a first device within the possession of a firstindividual within a proximity of the street light, wherein the firstindividual is one of a pedestrian and a cyclist, the first signal beingreceived via a near field communication (NFC) technology; a processor;and a memory storing instructions that, when executed by the processor,cause the alert control device to: determine that the first individualintends to cross a street within the proximity of the street light, saiddetermining being based on the first signal received from the firstdevice within the possession of the first individual; as a result ofdetermining that the first individual intends to cross the street,control the street light to go from a normal state to a first alertstate, wherein the lighting of the street light in the first alert statediffers from the lighting of the street light in the normal state inorder to alert passing vehicles that the first individual may becrossing the street within the proximity of the street light; receive asecond signal transmitted by a second device within the possession of asecond individual; determine that a NFC signal from the second devicehas not been received; and based on the receipt of the second signal andthe determination that the NFC signal from the second device has notbeen received, determine that the second individual is within theproximity of the street light but does not intend to cross the street.12. The alert control device of claim 11, wherein the first alert stateinvolves an altered color compared to the normal state.
 13. The alertcontrol device of claim 11, wherein the first alert state involves analtered light intensity compared to the normal state.
 14. The alertcontrol device of claim 11, further comprising instructions that, whenexecuted by the processor, causes the alert control device to: detect anabsence of any radio frequency identification devices using thereceiver; and control the street light to go from the alert state to thenormal state.
 15. The alert control device of claim 14, wherein theinstructions to detect an absence of any radio frequency identificationdevices comprise instructions that, when executed by the processor,causes the alert control device to detect an absence of any radiofrequency identification devices during a configurable time period. 16.The alert control device of claim 11, wherein the alert control deviceis connected to two street lights on either side of a road and the alertcontrol device is arranged to control both street lights the same way.17. The alert control device of claim 11, wherein at least one of thefirst signal and the second signal is received via a battery poweredradio frequency identification device which is activated by a user. 18.The alert control device of claim 11, further comprising instructionsthat, when executed by the processor, causes the alert control deviceto: store log data regarding when the street light is controlled to gofrom a normal state to the first alert state has occurred.
 19. A streetlight comprising the alert control device of claim
 11. 20. Anon-transitory computer readable medium on which a computer programcomprising computer program code is stored, the computer program codecomprising instructions which, when run on an alert control deviceconnected to a street light, cause the alert control device to:determine that a first individual intends to cross a street within theproximity of the street light, said determining being based on a firstsignal received from a device within the possession of the firstindividual, the first signal being received via a near fieldcommunication (NFC) technology; as a result of determining that thefirst individual intends to cross the street, control the street lightto go from a normal state to a first alert state, wherein the lightingof the street light in the first alert state differs from the lightingof the street light in the normal state in order to alert passingvehicles that the first individual may be crossing the street within theproximity of the street light; receive a second signal transmitted by asecond device within the possession of a second individual; determinethat a NFC signal from the second device has not been received; andbased on the receipt of the second signal and the determination that theNFC signal from the second device has not been received, determine thatthe second individual is within the proximity of the street light butdoes not intend to cross the street.
 21. The alert control device ofclaim 11, wherein the first signal is detectable over a maximum range ofapproximately 10 centimeters.
 22. The alert control device of claim 11,wherein the alert control device is further configured to control thestreet light to enter a second alert state in response to determiningthat the second individual is within the proximity of the street lightbut does not intend to cross the street, wherein the lighting of thestreet light in the second alert state differs from the lighting of thestreet light in the first alert state.
 23. A method for alertingtraffic, the method being performed in an alert control device connectedto a street light, the street light having a normal state, a first alertstate configured to alert passing vehicles that persons may be crossingthe street within a proximity of the street light, the first alert statebeing further configured to be triggered based on the alert controldevice receiving one or more near field communication (NFC) signals, anda second alert state, the second alert state differing from the normalstate and the first alert state, the method comprising: receiving afirst signal transmitted by a device within the possession of anindividual within a proximity of the street light; determining that anNFC signal from the device has not been received; and based on thereceipt of the first signal and the determination that the NFC signalfrom the device has not been received, determining that the individualis within the proximity of the street light but does not intend to crossthe street; as a result of determining that the individual is within theproximity of the street light but does not intend to cross the street,controlling the street light to enter the second alert state, the secondalert state being configured to alert passing vehicles that theindividual is within the proximity of the street light but does notintend to cross the street.